cURL to Code Converter

How the CURL Converter works

Curl to code converter: flags mapped to code

Every API documents its endpoints as curl commands, because curl is the one HTTP client everybody has. Almost nobody ships curl commands, so the first thing you do with the example is translate it, and translation is exactly the kind of mechanical work that goes wrong when you are in a hurry — a header dropped here, a body sent as a form instead of JSON there.

The method is inferred, not always stated. A curl command with no -X sends a GET unless there is a body, in which case it sends a POST. Documentation frequently relies on that, so a command showing only -d is a POST even though nothing says so. Getting this wrong produces a request that reaches the right URL and does the wrong thing, and the error message you get back rarely points at the method.

JSON bodies and form bodies are genuinely different requests. -d '{"a":1}' with a JSON content type is a JSON body; the same -d without that header is form-encoded, and curl will send Content-Type: application/x-www-form-urlencoded by default. This is the single most common translation bug: fetch will happily send your JSON string with the wrong content type, and the server will reject it with a message about invalid form data that gives no hint of the real cause. The converter reads the content type you supplied and picks the matching code shape.

Basic auth in curl is a flag, not a header. -u user:pass tells curl to base64-encode the pair and build the Authorization header itself. Neither fetch nor requests does that from a username and password string, so the translation has to be explicit — Axios and requests both take an auth parameter, and fetch needs the encoded header constructed by hand.

Multipart form fields are an approximation. -F name=value tells curl to build a multipart/form-data body with a generated boundary. A few targets have a first-class way to express that — FormData in the browser, files= in requests — and those get the real thing. Everywhere else the fields are folded into an ordinary URL-encoded body, which is the right shape for simple text fields. File uploads (-F field=@file) are not converted: the tool says so, and you add the file with the target language's own multipart helper.

curl does not follow redirects unless you ask it to. Without -L, a 301 or 302 comes back as the response. Browser fetch does the opposite and follows by default, and requests follows for most methods too. If the original command lacked -L, the faithful translation is one that disables redirect following — otherwise your code silently does something curl never did.

Copying a command out of your browser's network tab is a security decision. "Copy as cURL" includes every cookie and authorisation header from that session, which is what makes it work and also what makes it a live credential. Strip the session headers before pasting the command anywhere, this tool included — everything here runs locally, but the same command pasted into a chat or an issue tracker is a leaked token.

Related tools